Veterynarna biotehnologija – Veterinary biotechnology, 2016, 29, 55-61 [in Ukrainian].
BOYKO P.K., e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it., PALAMARCHYK A.M., e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Institute of Veterinary Medicine of the NAAS
COMPARATIVE OF ANALYSIS MORPHOLOGICAL CHARACTERISTICS, TINCTORIAL AND BIOCHEMICAL PROPERTIES OF PASTEURELLA MUSEUM STRAINS AND FIELD ISOLATES
Introduction. The comparative study of morphological, tinctorial, culture and biochemical properties and affiliation with serological groups of the Pasteurella field isolates and P. multocida and P. haemolytica museum strains. It was established,that by studying of cultural and biochemical properties, P. multocida can be different from P. haemolytica.
The goal of the work. To give the comparative characteristic of a number of Pasteurella field isolates, which could be used as productive strains for constructing vaccines against pasteurellosis of rabbits and controls for studying protective activities of the constructed vaccine preparations.
Materials and methods. 30 field isolates of Pasteurella were isolated from pathological material of rabbits. For comparative characteristics of P. multocida and P. haemolytica museum strains have been taken. In our work we used microscopic and culturally-biochemical research methods. Cultural properties of Pasteurella were studied in beef-extract broth (BEB), beef-extract agar (BEA), blood beef-extract agar (BBEA), McConkey agar and Hottinger’s agar. Cultivation was carried out at 37 ± 0,3˚C within 24 hours. Morphological characteristics and tinctorial properties were studied in preparations: a) for conventional light microscopy that were fixe on the flame and stained by Gram and Gins; b) for phase-contrast microscopy - preparation called “flatten drop” From biochemical values we determined the ability to form indole and urease, the presence of ornithine decarboxylase and saccharolytic activity to glucose, lactose, sucrose, maltose and mannitol on Hissa medium with the mentioned sugars. Belonging Pasteurella to serogroups was determined by two methods - with modified Campo test and flocculation reaction with aqueous solution of acriflavin.
Results of research and discussion. In the BEA as museum strains so field isolates formed same rounded, convex, smooth and translucent colonies that look like drops of dew. The growth of P. multocida in BEB is characterized by formation of uniform turbidity and mucous sludge, which rises then of shaking as braids, while P. haemolytica did not forms a sludge. In BBEA Pasteurella formed small dewy colonies, but only P. haemolytica,that grows on McConkey agar, causes hemolysis, while P. multocida does not grow in this medium. The use of BBEA and McConkey agar is an inexpensive and reliable criterion for differentiating these two Pasteurella strains. Field isolates and P. multocida museum strain had the same biochemical properties: produced indole, had an ornithine decarboxylase activity, had not urease, fermenting acids with glucose, sucrose and mannitol, did not fermentate maltose, except the isolate №3. As a result of CAMP tests we considered, that the Pasteurella isolates №1 and №2 belong to serogroup A. By results of mixing suspension with acriflavin, isolate №3 was designate as P. multocida serogroup D.
Conclusions and prospects for further research: 1. According to morphological characteristics and tinctorial properties P. haemolytica and P. multocida museum strains as well as Pasteurella field isolates didn’t have any differences, except of the capsule presence and size of the, which may be associated with virulence of Pasteurella isolates. 2. It is possible to out an accurate Pasteurella typing us the modified CAMP test and flocculation reaction with acriflavin, when type-specific agglutinating sera are not available. 3. Further studies will be directed to investigate virulent, antigenic and immunogenic properties of Pasteurella field isolates.
Keywords: Pasteurella, isolates, serogroups.
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